docs: def _find_year_for_season(league):
      """
      Return the necessary seaons's year based on the current date.
  
      Since all sports start and end at different times throughout the year,
      simply using the current year is not sufficient to describe a season. For
      example, the NCAA Men's Basketball season begins in November every year.
      However, for the November and December months, the following year is used
      to denote the season (ie. November 2017 marks the start of the '2018'
      season) on sports-reference.com. This rule does not apply to all sports.
      Baseball begins and ends in one single calendar year, so the year never
      needs to be incremented.
  
      Additionally, since information for future seasons is generally not
      finalized until a month before the season begins, the year will default to
      the most recent season until the month prior to the season start date. For
      example, the 2018 MLB season begins in April. In January 2018, however, not
      all of the season's information is present in the system, so the default
      year will be '2017'.
  
      Parameters
      ----------
      league : string
          A string pertaining to the league start information as listed in
          SEASON_START_MONTH (ie. 'mlb', 'nba', 'nfl', etc.). League must be
          present in SEASON_START_MONTH.
  
      Returns
      -------
      int
          The respective season's year.
  
      Raises
      ------
      ValueError
          If the passed 'league' is not a key in SEASON_START_MONTH.
      """
      today = _todays_date()
      if league not in SEASON_START_MONTH:
          raise ValueError('"%s" league cannot be found!')
      start = SEASON_START_MONTH[league]['start']
      wrap = SEASON_START_MONTH[league]['wrap']
      if wrap and start - 1 <= today.month <= 12:
          return today.year + 1
      elif not wrap and start == 1 and today.month == 12:
          return today.year + 1
      elif not wrap and not start - 1 <= today.month <= 12:
          return today.year - 1
      else:
          return today.year